This invention relates generally to the collection and analysis of machine diagnostic data, such as vibration data, temperature, and rotation speed. More particularly, this invention relates to a wireless sensor network and a method for monitoring a plurality of machines.
Many types of machines are used in a production or manufacturing facility, such as in the production of consumer and industrial goods and in the delivery of basic utility services. Because of the importance of these machines in meeting production and service requirements, taking a machine offline unexpectedly due to a failure can be costly. Accordingly, it is desirable to implement an effective predictive maintenance program to keep the machines in good working condition. Examples of such machines for which it is desirable to collect data for preventive maintenance are motors, pumps, generators, compressors, lathes and other machines having rotating or other moving parts, such as a shaft, rotor, or bearings.
Most predictive maintenance programs include the periodic collection of machine data, such as vibration data, rotation speed, and temperature. Vibration data is sensed using an accelerometer. Rotation is sensed by a tachometer. Temperature is sensed with a temperature sensor. Data collection previously has involved an operator carrying a data collection unit, sensors, and cables from machine to machine. A sensor is mounted at a test point on a given machine, then coupled to the data collection unit by a cable. The operator then operates the data collection unit to gather the data. The operator performs a route of a facility to gather data from one or more test points of one or more machines. Typically, the data then is uploaded from the data collection unit to a data analysis system where condition monitoring is performed, so as to provide early fault detection and efficiently schedule maintenance of a machine.
Wireless sensors have reduced the need for an operator to carry cables along a data collection route. The sensors instead communicate wirelessly with the data collection unit under the control of the operator walking the route. In some instances wireless sensors have been permanently installed at machine test points. These advances have allowed data acquisition to become more efficient.
More efficient data acquisition also has led to more data acquisition. However, the analysis of acquired data to diagnose a machine often requires special expertise. Thus, more data has led to the need for more special expertise. As an industrial trend, however, there are fewer technicians able to analyze machine diagnostic data for predicting faults and for identifying a need to perform machine maintenance so as to avoid unexpected failures of rotating machines.
Accordingly, the acquisition of more data has led to the need for more efficient and effective analysis of machine diagnostic data. The shortage of experts with the required expertise has led to the need for allocating the time of technicians having such expertise more efficiently. These and other needs are addressed by various embodiments of the present invention.